[Mustangscotty]

What's the trans temp when it's running hot? 200 degree's is ok for the engine temp but when the hotter summer temps hit, you could end up with trouble.

Does your trans fluid have any trash in it? Black spec's or does it smell burn't? No slippage when accelerating right?

Does the car roll ok with the engine shut off and trans in neutral? (Make sure your brakes are not partially engaged, e-brake included and bearings are good to go).

How much pressure is in the cooling system? Is the coolant circulating well?
Fan belt slipping at all? Coolant clean?

Whats your A/F look like? EGT's? Is there a loss of power when driving through the rpm's? What's the idle set at? Timing ok? Vac leaks from hoses or intake leaks?

Is the electric fan turning at full rpm? Using a relay and temp sensor? Do you use an expansion tank hooked up to the radiator and is it clean (inside)?

Correct range of spark plug installed? Air trapped in the engine?

Good luck, overheating sucks..